commit 82eb03cfd862a65363fa2826de0dbd5474cfe5e2 Author: Chip Coldwell Date: Mon Feb 16 13:11:56 2009 +0100 cciss: PCI power management reset for kexec The kexec kernel resets the CCISS hardware in three steps: 1. Use PCI power management states to reset the controller in the kexec kernel. 2. Clear the MSI/MSI-X bits in PCI configuration space so that MSI initialization in the kexec kernel doesn't fail. 3. Use the CCISS "No-op" message to determine when the controller firmware has recovered from the PCI PM reset. [akpm@linux-foundation.org: cleanups] Signed-off-by: Mike Miller Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c index 132f76b..fecf524 100644 --- a/drivers/block/cciss.c +++ b/drivers/block/cciss.c @@ -3257,6 +3257,205 @@ static void free_hba(int i) kfree(p); } +/* Send a message CDB to the firmware. */ +static __devinit int cciss_message(struct pci_dev *pdev, unsigned char opcode, unsigned char type) +{ + typedef struct { + CommandListHeader_struct CommandHeader; + RequestBlock_struct Request; + ErrDescriptor_struct ErrorDescriptor; + } Command; + static const size_t cmd_sz = sizeof(Command) + sizeof(ErrorInfo_struct); + Command *cmd; + dma_addr_t paddr64; + uint32_t paddr32, tag; + void __iomem *vaddr; + int i, err; + + vaddr = ioremap_nocache(pci_resource_start(pdev, 0), pci_resource_len(pdev, 0)); + if (vaddr == NULL) + return -ENOMEM; + + /* The Inbound Post Queue only accepts 32-bit physical addresses for the + CCISS commands, so they must be allocated from the lower 4GiB of + memory. */ + err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK); + if (err) { + iounmap(vaddr); + return -ENOMEM; + } + + cmd = pci_alloc_consistent(pdev, cmd_sz, &paddr64); + if (cmd == NULL) { + iounmap(vaddr); + return -ENOMEM; + } + + /* This must fit, because of the 32-bit consistent DMA mask. Also, + although there's no guarantee, we assume that the address is at + least 4-byte aligned (most likely, it's page-aligned). */ + paddr32 = paddr64; + + cmd->CommandHeader.ReplyQueue = 0; + cmd->CommandHeader.SGList = 0; + cmd->CommandHeader.SGTotal = 0; + cmd->CommandHeader.Tag.lower = paddr32; + cmd->CommandHeader.Tag.upper = 0; + memset(&cmd->CommandHeader.LUN.LunAddrBytes, 0, 8); + + cmd->Request.CDBLen = 16; + cmd->Request.Type.Type = TYPE_MSG; + cmd->Request.Type.Attribute = ATTR_HEADOFQUEUE; + cmd->Request.Type.Direction = XFER_NONE; + cmd->Request.Timeout = 0; /* Don't time out */ + cmd->Request.CDB[0] = opcode; + cmd->Request.CDB[1] = type; + memset(&cmd->Request.CDB[2], 0, 14); /* the rest of the CDB is reserved */ + + cmd->ErrorDescriptor.Addr.lower = paddr32 + sizeof(Command); + cmd->ErrorDescriptor.Addr.upper = 0; + cmd->ErrorDescriptor.Len = sizeof(ErrorInfo_struct); + + writel(paddr32, vaddr + SA5_REQUEST_PORT_OFFSET); + + for (i = 0; i < 10; i++) { + tag = readl(vaddr + SA5_REPLY_PORT_OFFSET); + if ((tag & ~3) == paddr32) + break; + schedule_timeout_uninterruptible(HZ); + } + + iounmap(vaddr); + + /* we leak the DMA buffer here ... no choice since the controller could + still complete the command. */ + if (i == 10) { + printk(KERN_ERR "cciss: controller message %02x:%02x timed out\n", + opcode, type); + return -ETIMEDOUT; + } + + pci_free_consistent(pdev, cmd_sz, cmd, paddr64); + + if (tag & 2) { + printk(KERN_ERR "cciss: controller message %02x:%02x failed\n", + opcode, type); + return -EIO; + } + + printk(KERN_INFO "cciss: controller message %02x:%02x succeeded\n", + opcode, type); + return 0; +} + +#define cciss_soft_reset_controller(p) cciss_message(p, 1, 0) +#define cciss_noop(p) cciss_message(p, 3, 0) + +static __devinit int cciss_reset_msi(struct pci_dev *pdev) +{ +/* the #defines are stolen from drivers/pci/msi.h. */ +#define msi_control_reg(base) (base + PCI_MSI_FLAGS) +#define PCI_MSIX_FLAGS_ENABLE (1 << 15) + + int pos; + u16 control = 0; + + pos = pci_find_capability(pdev, PCI_CAP_ID_MSI); + if (pos) { + pci_read_config_word(pdev, msi_control_reg(pos), &control); + if (control & PCI_MSI_FLAGS_ENABLE) { + printk(KERN_INFO "cciss: resetting MSI\n"); + pci_write_config_word(pdev, msi_control_reg(pos), control & ~PCI_MSI_FLAGS_ENABLE); + } + } + + pos = pci_find_capability(pdev, PCI_CAP_ID_MSIX); + if (pos) { + pci_read_config_word(pdev, msi_control_reg(pos), &control); + if (control & PCI_MSIX_FLAGS_ENABLE) { + printk(KERN_INFO "cciss: resetting MSI-X\n"); + pci_write_config_word(pdev, msi_control_reg(pos), control & ~PCI_MSIX_FLAGS_ENABLE); + } + } + + return 0; +} + +/* This does a hard reset of the controller using PCI power management + * states. */ +static __devinit int cciss_hard_reset_controller(struct pci_dev *pdev) +{ + u16 pmcsr, saved_config_space[32]; + int i, pos; + + printk(KERN_INFO "cciss: using PCI PM to reset controller\n"); + + /* This is very nearly the same thing as + + pci_save_state(pci_dev); + pci_set_power_state(pci_dev, PCI_D3hot); + pci_set_power_state(pci_dev, PCI_D0); + pci_restore_state(pci_dev); + + but we can't use these nice canned kernel routines on + kexec, because they also check the MSI/MSI-X state in PCI + configuration space and do the wrong thing when it is + set/cleared. Also, the pci_save/restore_state functions + violate the ordering requirements for restoring the + configuration space from the CCISS document (see the + comment below). So we roll our own .... */ + + for (i = 0; i < 32; i++) + pci_read_config_word(pdev, 2*i, &saved_config_space[i]); + + pos = pci_find_capability(pdev, PCI_CAP_ID_PM); + if (pos == 0) { + printk(KERN_ERR "cciss_reset_controller: PCI PM not supported\n"); + return -ENODEV; + } + + /* Quoting from the Open CISS Specification: "The Power + * Management Control/Status Register (CSR) controls the power + * state of the device. The normal operating state is D0, + * CSR=00h. The software off state is D3, CSR=03h. To reset + * the controller, place the interface device in D3 then to + * D0, this causes a secondary PCI reset which will reset the + * controller." */ + + /* enter the D3hot power management state */ + pci_read_config_word(pdev, pos + PCI_PM_CTRL, &pmcsr); + pmcsr &= ~PCI_PM_CTRL_STATE_MASK; + pmcsr |= PCI_D3hot; + pci_write_config_word(pdev, pos + PCI_PM_CTRL, pmcsr); + + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ >> 1); + + /* enter the D0 power management state */ + pmcsr &= ~PCI_PM_CTRL_STATE_MASK; + pmcsr |= PCI_D0; + pci_write_config_word(pdev, pos + PCI_PM_CTRL, pmcsr); + + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ >> 1); + + /* Restore the PCI configuration space. The Open CISS + * Specification says, "Restore the PCI Configuration + * Registers, offsets 00h through 60h. It is important to + * restore the command register, 16-bits at offset 04h, + * last. Do not restore the configuration status register, + * 16-bits at offset 06h." Note that the offset is 2*i. */ + for (i = 0; i < 32; i++) { + if (i == 2 || i == 3) + continue; + pci_write_config_word(pdev, 2*i, saved_config_space[i]); + } + wmb(); + pci_write_config_word(pdev, 4, saved_config_space[2]); + + return 0; +} + /* * This is it. Find all the controllers and register them. I really hate * stealing all these major device numbers. @@ -3270,6 +3469,24 @@ static int __devinit cciss_init_one(struct pci_dev *pdev, int rc; int dac; + if (reset_devices) { + /* Reset the controller with a PCI power-cycle */ + if (cciss_hard_reset_controller(pdev) || cciss_reset_msi(pdev)) + return -ENODEV; + + /* Some devices (notably the HP Smart Array 5i Controller) + need a little pause here */ + schedule_timeout_uninterruptible(30*HZ); + + /* Now try to get the controller to respond to a no-op */ + for (i=0; i<12; i++) { + if (cciss_noop(pdev) == 0) + break; + else + printk("cciss: no-op failed%s\n", (i < 11 ? "; re-trying" : "")); + } + } + i = alloc_cciss_hba(); if (i < 0) return -1;